Structural And Optical Properties Study Of ZnO Thin Films Grown By Atmospheric Pressure MOCVD

ZnO is a suitable candidate material for short wavelength device after GaN. Applicable ZnO optoelectronic devices have not been fabricated, though p-i-n LED has initially come true. The reason is the quality of ZnO thin film need to be improved ulteriorly. The affected factors of the quality of ZnO thin film have a good many. The different process and source material can affect the properties of ZnO epitaxial layers.It is still in initial stage for ZnO film grown by metal organic chemical vapor deposition, especially it is in grope stage for selection of source materials. It is still disputed Which O precursor fit to grown ZnO on earth. In addition strain can induce piezoelectricity in ZnO film and it will affect the life of device in the future. So it is necessary to carry out these study. The concent of this article consists of two parts:The first part: High-quality ZnO films were grown on C-Al₂O₃ substrate by atmospheric pressure metal organic chemical vapor deposition (AP-MOCVD) technique, using a method of three-step growth. Zn(C₂H₅)₂ and H₂O were used as the Zn and O precursor in both the low and high temperature buffers and nitrous oxide(N₂O) was used as 0 precursor in the main ZnO layer. Then high quality ZnO films were grown, using H₂O as O source entirely. Two samples were analysed by double crystal X-ray diffraction (DCXRD) and PL spectra, respectively. Compared with their structure and optical properties. From which some encouraging results are as follows:1. ZnO film were analysed by double crystal X-ray diffraction (DCXRD). The results indicated that high quality ZnO film had been grown to use N₂O as O precursor. The full widths at half maximum (FWHM) of the (10-12) Omega rocking curves of the ZnO film by double crystal X-ray diffraction (DCXRD) were 350arcsec.2. Compared with the 10K low temperature PL spectra of the H₂O-grown ZnO sample, the two electron satellite(TES) of 3. 331eV in relation to hydrogen was disappeared in that of the NiO-growth ZnO sample. It shows that hydrogen atom is not easily introduced in the N₂O-growth ZnO film. It is in favor of p-type doping in the future. We observed three LO phonon replicas of A free exciton in low temperature PL spectra of the N₂O-growth ZnO...